The RACE amplifying and sequence analyzing of secreted aspartic proteinase gene SA76 of Trichoderma harzianum

Total RNA was isolated from mycelium of T. harzianum by Total RNA extraction kit, and two clear bands of rRNA （28S and 18S） were observed in agarose electrophoresis. By joining the 3＇end sequence with the known SA76 EST from cDNA library of T. harzianum, a full-length cDNA sequence of 2019bp was obtained, whose open reading frame contained 1593bp, a stop codon TAA, a 5＇untranslated region （5＇UTR） of 266bp, a 3＇untranslated region （3＇UTR） of 201bp, and poly （A） 29 encoded a protein of 530 amino acids, had a signal peptide. T. harzianum shared 53% identity of secreted aspartic proteinase gene with G. zeae, 37% with N. crassa and 36% with C. globosum. The full-length cDNA sequence of secreted aspartic proteinase gene from T. harzianum was cloned for the first time by using BD SMART RACE technique, which provides a foundation to obtain and validate functional genes of T. harzianum.

Effects of Tribulus terrestris saponins on proliferation and invasion of A549 cells

Objective:Tribulus terrestris saponin is a traditional Chinese medicine in China.This experiment was designed to investigate the effects of tribulus terrestris saponin on the proliferation and invasion ability of non-small cell lung cancer A549 cells.Methods:A549 cells were divided into normal control and experimental groups(Tribulus terrestris saponin 250μg/mL group,Tribulus terrestris saponin 200μg/mL group,Tribulus terrestris saponin 150μg/mL group,Tribulus terrestris saponin 100μg/mL group,Tribulus terrestris saponin 50μg/mL group).The proliferation viability of the cells in each group was detected by CCK8,the invasion of tumor cells was detected by Transwell model.The mRNA expression of MMP9 and caspase-3 in each group of cells was detected by RT-PCR.Immunofluorescence staining was used to observe the fluorescence intensity of caspase-3 in each group of cells.Results:Compared with the normal control group,tribulus terrestris saponin significantly inhibited the proliferation activity and invasion ability of A549 cells,which was statistically significant(P<0.01).In the invasion assay,compared with the control group,MMP9 expression was significantly reduced and caspase-3 expression was significantly increased in the tribulus terrestris saponin group,and both were concentration-dependent,with statistically significant differences(P<0.01).By cellular immunofluorescence staining experiments,it was found that the fluorescence expression of caspase-3 was enhanced in the experimental group compared with the normal control group,in which the high concentration saponin group was significantly higher than the low concentration group.Conclusion:Tribulus terrestris saponin can inhibit the invasive ability of A549 cells by down-regulating the expression of MMP9,and induce irreversible apoptosis by up-regulating the activation of caspase-3 expression to form caspase-3.